In 2007, Laurie David, producer of An Inconvenient Truth, ex-wife of Larry David, and self-described “global warming activist,” published The Down To Earth Guide to Global Warming, a book for children. It contained a graph showing the very strong correlation over time between carbon dioxide levels and global temperature. The point was that carbon dioxide controlled global temperature. But there was a problem: The graph was mislabeled. The function labeled “carbon dioxide” was actually the temperature function. Correctly labeled, the graph showed that carbon dioxide changes followed temperature changes. Which meant that the temperature changes had caused the carbon-dioxide changes, rather than the other way around — which was one of the book’s main points.
David’s reaction to the mistake?
Thanks guys! We will correct the illustration in the next edition. We’re happy to learn that that was the only question SPPI had about the entire fact-filled book!
As if it’s trivial.
Moral: A sign of things to come.
More The fact that a producer of An Inconvenient Truth, the movie that arguably won Al Gore a Nobel Prize, could (a) make such a basic mistake and (b) dismiss it as trivial is the ladies-who-lunch equivalent of the fact that Jones and other CRU scientists were scared of a New York Times reporter.
Seth, it’s sad to see you descending into full-on crankhood. How is it that CO2 followed prehistorical temperature fluctuations by centuries, yet tracks the rise directly today? It’s fortunate you and your new compatriots weren’t able to involve yourselves in forestalling efforts to protect the ozone layer.
That said, efforts to reduce CO2 emission sufficiently by regulation are doomed. We should be sluicing money into research and development of technologies that will come to produce energy more cheaply than burning fossil fuels. Taxing fossil fuel use would be a practical source of money to pay for it, and of (local, temporary) artificial competitiveness for the new products of such development. After fossil fuels have been rendered relatively more expensive, the nations that developed the practical alternatives will benefit from first-mover advantage. The furnaces will crumble of their own accord, unlamented.
Why does CO2 now go up at the same time as global temperature? Because now a lot of carbon dioxide is man-made. Nathan, why are you sure that people who question man-made global warming are cranks?
The phenomena is well-known to climate scientists and they explain it (away?) as
some currently unknown forcing that heats the planet for 800 years, and also causing increase in Co2. The increasing Co2 positively reinforces the previous small heating from the unknown cause. The Co2-caused heating is 80% of the
total heating and 20% is the heating in first 800 years.
This is from realclimate.org
Scientists shouldn’t be needing to add auxiliary hypotheses until their primary hypotheses is established as having some plausibility.
First you state your hypothesis in explicit detail and state its predicted consequences (e.g. a specific mathemetical model might be the ‘hypothesis’ – although in fact a mathemetical model isn’t really an hypothesis when it is derived post hoc from the data it is aiming to explain – an hypotheses really ought to be causal rather than merely statistical) – then you test the predicted observations against a new set of observations; naturally this must be done without changing the hypotheses to fit the new observations.
Until a post hoc statistical model has been tested against new observations it has zero credibility.
And until the post hoc model has been tested, it has zero predictive value, and we have zero idea about what will happen in the future.
But all this is absolutely basic. The fact that so many people don’t understand it simply means that they are not scientists at all, not even a little bit. They are merely technicians – whether good or bad technicians, whether honest or dishonest.
I should maybe spell out my point even more clearly.
The debate is not about whether global warming has happened, the debate is about whether we _understand_ the causes of global climate to the extent that we can predict the future climate.
My point is that – because the predictions of ‘the’ computer model was not tested against new observations (but instead was repeatedly adjusted to more closely describe already-existing past observations) – there is zero evidence that we understand the causes of global climate. Therefore we cannot make scientific predictions.
Since we cannot even predict climate, it should not really be necessary to add that there is also (to put it as mildly as possible) zero evidence that humans can control the global climate.
Anyone rational who _really_ believed the guesses (not scientific predictions) of significant future global warming would want to use our limited resources to _prepare_ for global warming; rather than engaging in the utterly ignorant, wasteful, distracting, dishonest nonsense of trying to prevent something we do not understand.
Nathan, if CO2 used to follow temperature but now tracks it (which I’m not sure we know, or you know), then what is the point of looking at historical graphs? What hypothesis about CO2 and warming does it support? This is an especially puzzling question given that apparently to AGW believers you can interchange CO2 and temperature willy-nilly, show the interchanged graph, and still be (supposedly) proving the same point.
It’s as Bruce says, if you don’t have or know a mechanism for what you think you’re predicting, such graphs are useless.
Here is a realclimate post on the topic. Briefly:
– ice core data show that temperatures increased for a few thousands years at the end of glacial periods, and CO2 levels started increasing a few hundred years after temperatures started increasing (so both rose together after the first few hundred years)
– climate scientists have recognized this at least since 1990
– climate scientists have concluded that CO2 acted as a positive feedback mechanism that kicked in after warming started for other reasons
– their best guesses seem to be that orbital forcing caused the initial warming and that the feedback carbon mainly came from the oceans
– when analyzing the data, it’s not possible to account for the amount of warming unless you give a causal role to CO2 and other greenhouse gases
– the data imply that greenhouse gases were responsible for about a third of the warming
– climate models and predictions are based on other information, not on these historical records from ice ages, but these data do suggest fairly similar predictions of future warming due to rising greenhouse gases
Looking through realclimate a bit more, it looks like ice cores provide another example of accurate predictions by climate scientists. Climate scientists had data on atmospheric concentrations of greenhouse gases going back only a few hundred thousand years, and they were going to gather data on atmospheric GHGs going back farther (up to 650,000 years ago), so they made predictions of what they would find based on their knowledge of temperatures from that time period, their knowledge about other causes of temperature variation, and their model of how GHGs influence the temperature. The idea was that temperature variation that wasn’t accounted for by the other factors was probably due to the unmeasured GHGs influencing temperature in accordance with their models. And apparently their predictions were pretty good.
Seth: It would take just as much work to demonstrate that CO2 is not the main cause of global warming as has gone into proving that it is, but you’re trying to do it with parlor tricks instead.
Bruce: This use of “technician” as an insult is nothing better than bigotry. Your family doctor is a technician. Scientists who pay close attention to technicians become better scientists, because technicians have the most contact with the data and their sources.
Nathan, I asked you: Why are you so sure that people who question AGW are cranks? Your answer is: “It would take just as much work to demonstrate that CO2 is not the main cause of global warming as has gone into proving that it is, but you’re trying to do it with parlor tricks instead”? Huh? I suppose you’re ignoring my question, but I’m not sure.
I think he thinks you are a crank because you didn’t bother to do a basic Google search and figure out for your self why this isn’t a big deal, and instead decided to make mountains out of moll hills.
Allso are you going to address Vince?
Seth, I’m not saying “people who question AGW” are cranks, although many are. I’m talking about your own behavior. It’s completely legitimate to question mainstream science and industry, but not to seize on trivialities.
The Ares rocket is a positively idiotic design, obviously driven by the politics of patronage, to the exclusion of the most basic sense. Minor mistakes would be invisible or incomprehensible to me, but its are so gross even I can’t miss them.
Nathan, thanks for explaining that. It is my mission in life to hold Laurie David accountable.
I’ve looked at the graph in question, and at the annotation given by the authors, and at no point do they mention anything about leading or lagging of the two data sets, only that they are correlated — which of course is true independent of which is which. Furthermore there is only really a lag in temperature at two points, otherwise they’re mostly in sync. So whereas this (corrected) graph admittedly shows only correlation and not causation, it certainly in no way disproves either.
Therefore there is every reason to believe this was just a simple mistake, easily overlooked by even the most experienced climate scientist. And to flap your hands around and scream “Look here! They’re lying!” because of it is intellectually dishonest at best.
Yeah, Seth don’t seize on trivialities like the perihelion shift of Mercury. Ignore it. Newton was right.